15. f1d1 This makes things worse. It's better for White to abandon the d-pawn immediately. 15... g7g6 A mistake in return. 16. a3a4 A good move, preparing Ba3 or Ra3 to defend the d-pawn if necessary. 16... h7h5 A tempting move to develop the bishop on h6, but it is better to remove the queen from c7 first. 17. b5b6 